Rock Falls Illinois Climate Data

Monthly Average Climate Data for Rock Falls Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January13.1 °F29.5 °F1.71 in.
February16.9 °F34.0 °F1.72 in.
March27.4 °F46.6 °F2.39 in.
April38.0 °F60.2 °F3.83 in.
May50.0 °F71.6 °F4.92 in.
June59.8 °F80.7 °F5.42 in.
July63.0 °F83.6 °F4.28 in.
August60.9 °F81.9 °F4.28 in.
September52.5 °F76.0 °F3.76 in.
October40.8 °F63.1 °F2.81 in.
November29.7 °F47.7 °F2.29 in.
December19.7 °F35.1 °F1.94 in.
Annual39.3 °F59.2 °F39.35 in.

Climate Data for Rock Falls Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsNormal
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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